Unusually Massive Line of Storms Menaces U.S.
June 12, 2013
AP - A gigantic line of powerful
thunderstorms could affect one in five Americans on Wednesday as it
rumbles from Iowa to Maryland packing hail, lightning and tree-toppling
winds.
Meteorologists are warning that
the continuous line of storms may even spawn an unusual weather event
called a derecho (duh-RAY'-choh), which is a massive storm of strong straight-line winds
spanning at least 240 miles. Wednesday's storms are also likely to
generate tornadoes and cause power outages that will be followed by
oppressive heat, said Bill Bunting, operations chief at the National Weather Service's Storm Prediction Center in Norman, Okla.
The risk of severe weather in Chicago,
Indianapolis, Cincinnati and Columbus, Ohio, is roughly 45 times higher
than on a normal June day, Bunting said. Detroit, Baltimore,
Washington, Milwaukee, Pittsburgh and Louisville, Ky., have a risk level
15 times more than normal. All told, the area the weather service considers to be under heightened risk of dangerous weather includes 64 million people in 10 states.
"It's a pretty high threat," Bunting said, who also warned that the
storms will produce large hail and dangerous lightning. "We don't want
to scare people, but we want them to be aware."
Wednesday "might be the worst severe weather outbreak for this part
of the country for the year," said Jeff Masters, meteorology director at
Weather Underground.
Tornadoes and a derecho can happen at the same time, but at any given
place Wednesday the straight-line winds are probably more likely.
Last year, a derecho caused at least $1 billion in damage from Chicago
to Washington, killing 13 people and leaving more than 4 million people
without power, according to the weather service. Winds reached nearly
100 mph in some places and in addition to the 13 people who died from
downed trees, another 34 people died from the heat wave that followed in
areas without power.
Derechoes, with winds of at least 58 mph, occur about once a year in the Midwest. Rarer than tornadoes but with weaker winds, derechoes produce damage over a much wider area.
Wednesday's storm probably won't be as powerful as 2012's historic
one, but it is expected to cause widespread problems, Bunting said.
The storms will move so fast that "by the time you see the dark sky
and distant thunder you may have only minutes to get to safe shelter,"
Bunting said.
The storms will start late morning or early afternoon in eastern
Iowa, hit Chicago by early afternoon and move east at about 40 mph,
Bunting said. If the storm remains intact after crossing the Appalachian
Mountains, which would be rare for a derecho, it should hit the
Washington area by late afternoon or early evening, he said.
For Washington, Philadelphia and
parts of the Mid-Atlantic the big storm risk continues and even
increases a bit Thursday, according to the weather service.